This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. We have recently shown that GnT-V expression levels regulate the mouse mammary cancer stem cell compartment resulting from her-2 over-expression. In addition, we have shown that glycans that are products of GnT-V are found in different levels on the her-2 receptor when the activity of GnT-V is modulated. We are now determining the precise structures of the N-linked glycans on the mammary tumors induced by her-2 and comparing those quantitatively with the structures expressed in the non-diseased mammary gland.